Having written IE11 to support web standards, Microsoft is shimming it to handle mobile websites that are not following standards but catering for webkit quirks and/or non-standard features in Apple's Safari on iOS.

It's no surprise that Firefox and Chrome won't run as desktop browsers on Windows RT devices; Microsoft has been saying all along that x86 apps wouldn't run on Windows on ARM and it explicitly said there would be no third-party code on Windows RT when it announced the details of the platform back in February.

Microsoft will restrict third-party browsers like Firefox and Chrome to the Metro sandbox in Windows 8 for ARM devices, while treating Internet Explorer 10 as an "intrinsic feature" of Windows. Mozilla and its primary backer, Google, say that's not fair.

Microsoft has accused Google of bypassing IE privacy preferences to track users as they surf the web, but Google says the workaround is necessary for modern web features such as Facebook 'Like' buttons

Mozilla is offering users the option of downloading a version of Firefox that uses Microsoft Bing as the default search engine.The company said it would offer the option in a post on the official Mozilla blog on Wednesday.

In a move that's sure to raise hackles in Silicon Valley, Microsoft today debuted a new web site designed to raise awareness of security issues in web browsers. IE9 gets a perfect score; Chrome and Mozilla don't. How fair is the test?